The Financial Times reported last week that discussions had started with banks, including Goldman Sachs, about launching an initial public offering for the group.
It is thought the flotation could happen this year.
The estate agency, which employs 10,500 people, has expanded its presence in London and stepped up its brokering division, arranging £4bn worth of mortgages in 2011.
The group posted sales of £509m in 2011 and had pre-tax profits of £35.7m, up a third on a year earlier. It ended the year with £189m of net debt.
Oaktree, Countrywide and Goldman declined to comment.
